(a) Field of the Invention
The invention concerns a motorized gate. More specifically, the invention is directed to a device enabling a gate to pivot while effecting a vertical lifting.
(b) Description of the Prior Art
It is known that many commercial and industrial buildings as well as some outlets, such as electrical substations, should be fenced in order to protect them against theft and/or vandalism and in certain cases, because they present a real danger even for the onlookers, such as children. Now, the persons in charge of the maintenance of these sites are often urgently called in to make repairs or to carry out operations which cannot be postponed. In such cases, it is nearly always necessary to penetrate inside the fenced in area with some equipment which implies that trucks or pick-ups and often other types of motorized vehicles must be brought inside the enclosure. If there was a sudden accumulation of an important quantity of snow, it is often impossible to open the gate without previously having removed that which prevents the opening of the gate. It will be understood that in urgent cases, it is not always possible to proceed to snow removal in the sector represented by the opening of the gate, without risking serious consequences. There is therefore a marked interest in having a gate conceived in such a manner as to enable a more or less important vertical elevation and which does not require a large frame.
In order to overcome the difficulties mentioned, I have invented a device enabling a gate to pivot while effecting a vertical lifting. The device comprises a vertical member, helicoidal guides on the vertical member, displacing means fixed on said gate, and means associated with the helicoidal guides enabling a vertical lifting of the gate while the displacing means follow a path determined by the helicoidal guides, which enable the gate to pivot and to open while effecting said vertical lifting.
According to a preferred embodiment of the invention, the helicoidal guides are made of metallic bars which are mounted on the vertical member.
According to another preferred embodiment of the invention, the vertical member is constituted by a metallic post. Preferably, the metallic bars are welded on the surface of the post.
According to another preferred embodiment of the invention, the metallic bars have a square cross-section.
The device preferably comprises two lower metallic bars opposed to one another and located at a same lower level, as well as two upper metallic bars, which are opposed to one another and located at a same upper level.
Each metallic bar preferably comprises a lower rectilinear portion which only permits a vertical lifting of the gate, followed by a helicoidal portion which enables a simultaneous vertical lifting of the gate and a pivoting of the latter, followed by an upper rectilinear vertical portion to complete the lifting of the gate.
Preferably, the displacing means are rolling means, for example, carriages.
According to another preferred embodiment of the invention, the device comprises a lower semi-annular element shaped to surround the post and an upper semi-annular element shaped to surround the post, a carriage being fixed at the two ends of each semi-annular element so that each carriage engages the corresponding metallic bar.
The semi-annular elements preferably comprise means intended to mount the gate.
According to another preferred embodiment of the invention, the two semi-annular elements are connected together by means of a rod to constitute a rigid assembly, the rod having a length such that, when there is a vertical displacement of the gate, the lower semi-annular element is at a level of the lower metallic bars which corresponds to the level of the upper metallic bars opposite which the upper semi-annular element is placed.
Even though any means known to those skilled in the art can be used to connect the gate to the device, it is preferable to have gate supports fixed on the semiannular elements so as to receive the gate.
According to a preferred embodiment of the invention, each carriage comprises an L-shaped element and two parallel blocks fixedly mounted rearwardly and at the ends of one of the legs of the L-shaped element, a longitudinal notch being formed in each block, an axle mounted between the two blocks, the ends thereof being capable of sliding within the notches, a bobbin-shaped roll mounted to roll freely over said axle, a bore provided in each of said blocks, the bore comprising a threaded portion, a coil spring disposed in said bore and resting against the axle by means of a gudgeon and a tightening screw mounted in the threaded portion of the bore and resting against the coil spring, two freely rotatable rollers mounted on the other leg of the L-shaped element so as to engage both sides of one of the metallic bars while the bobbin-shaped roller rests against the upper face of the corresponding metallic bar under the action of the coil spring, and a connecting member enabling the mounting of the carriage on the semi-annular element.
The connecting member preferably comprises a rod having one end welded on the other leg of the L-shaped element, a pipe surrounding the rod so as to rotate around said rod, the pipe being on the other hand welded at the end of the semi-annular element, thus enabling the carriage to pivot while following the path of the metallic bar.
The means enabling a vertical lifting of the gate preferably comprise a pulley and a cable mounted on the gate and winding around the pulley as well as a motor to move the cable and thereby lift the gate.